Nonaqueous electrolyte secondary battery and method of manufacturing the same
A nonaqueous electrolyte secondary battery includes: a wound electrode body that is formed by laminating an elongated sheet-shaped positive electrode current collector foil, an elongated sheet-shaped negative electrode current collector foil, and an elongated sheet-shaped separator to obtain a laminate and winding the obtained laminate; a nonaqueous electrolytic solution; and a case that accommodates the wound electrode body and the nonaqueous electrolytic solution. A solid electrolyte interface film derived from an oxalato borate complex is formed on at least a surface of the negative electrode active material layer. The positive electrode current collector foil satisfies the following conditions of (a) 700%≤α≤760% and (b) 530%≤β≤590%, where α represents a 60-degree specular gloss in a direction parallel to a longitudinal direction of the positive electrode current collector foil, and β represents a 60-degree specular gloss in a width direction perpendicular to the longitudinal direction of the positive electrode current collector foil.
1. A nonaqueous electrolyte secondary battery comprising:
a wound electrode body that is formed by laminating an elongated sheet-shaped positive electrode current collector foil, an elongated sheet-shaped negative electrode current collector foil, and an elongated sheet-shaped separator to obtain a laminate and winding the obtained laminate, in which the positive electrode current collector foil has a surface on which a positive electrode active material layer containing a positive electrode active material is formed, and the negative electrode current collector foil has a surface on which a negative electrode active material layer containing a negative electrode active material is formed;
a nonaqueous electrolytic solution; and
a case that accommodates the wound electrode body and the nonaqueous electrolytic solution, wherein
a solid electrolyte interface film derived from an oxalato borate complex is formed on at least a surface of the negative electrode active material layer, wherein a sodium component is present, and
the positive electrode current collector foil satisfies the following conditions of
700%≤α≤760% and (a)
530%≤β≤590% (b)
where α represents a 60-degree specular gloss, calculated using a measurement method according to JIS Z 8741:1997, in a direction parallel to a longitudinal direction of the positive electrode current collector foil, and
β represents a 60-degree specular gloss, calculated using a measurement method according to JIS Z 8741:1997, in a width direction perpendicular to the longitudinal direction of the positive electrode current collector foil, wherein
the positive electrode current collector foil is aluminum foil having an overall arithmetic average roughness of 0.08 μm to 0.12 μm.
2. The nonaqueous electrolyte secondary battery according to claim 1 , wherein
the oxalato borate complex is lithium bis(oxalato)borate.
3. A battery pack comprising:
a plurality of nonaqueous electrolyte secondary batteries that are electrically connected to each other, wherein
each of the plurality of nonaqueous electrolyte secondary batteries is the nonaqueous electrolyte secondary battery according to claim 1 .
4. A method of manufacturing a nonaqueous electrolyte secondary battery, the method comprising:
forming a wound electrode body by laminating an elongated sheet-shaped positive electrode current collector foil, an elongated sheet-shaped negative electrode current collector foil, and an elongated sheet-shaped separator to obtain a laminate and winding the obtained laminate, in which
the positive electrode current collector foil has a surface, on which a positive electrode active material layer containing a positive electrode active material is formed, and is adjusted to satisfy the following conditions of
700%≤α≤760% and (a)
530%≤β≤590% (b)
where α represents a 60-degree specular gloss, calculated using a measurement method according to JIS Z 8741:1997, in a direction parallel to a longitudinal direction of the positive electrode current collector foil, and
β represents a 60-degree specular gloss, calculated using a measurement method according to JIS Z 8741:1997, in a width direction perpendicular to the longitudinal direction of the positive electrode current collector foil, and
the negative electrode current collector foil has a surface on which a negative electrode active material layer containing a negative electrode active material is formed; and
accommodating a nonaqueous electrolytic solution and the wound electrode body in a battery case and impregnating the wound electrode body with the nonaqueous electrolytic solution from end portions of the wound electrode body in a width direction perpendicular to a longitudinal direction of the wound electrode body, in which
the nonaqueous electrolytic solution contains an oxalato borate complex capable of forming a solid electrolyte interface film on at least a portion of the negative electrode active material layer after charging, wherein
the positive electrode current collector foil is aluminum foil having an overall arithmetic average roughness of 0.08 μm to 0.12 μm, and a sodium component is present.
5. The method according to claim 4 , wherein
the nonaqueous electrolytic solution contains a lithium bis(oxalato)borate as the oxalato borate complex.